Virtual Assessment of air Pollution Dispersion from Anthropogenic Sudden Explosion

Marvel Lola Akinyemi,Mojisola Rachel Usikalu,Moses Eterigho Emetere

doi:10.3844/ajessp.2016.94.101

Abstract

The control of air pollutants from anthropogenic sources seems almost impossible due to numerous influencing factors present in the atmosphere. In this study, we carried out a virtual mathematical experimentation using Math CAD, Mat lab and analytical approximation to estimate the dimensional impact of initial pollutant plume cloud from a sudden volcanic blast and the dynamics of its wind field. The high point of the experimentation is the period of the first one-tenth of a second (1 decisecond) to 1 min (60 s) of the blast at the point source. We also assessed the long range air pollution dispersion within the first 1 to 10 min of plume cloud released under practical assumptions. The model revealed a plume cloud impact of 6.8×107 μgm−3 in the first 1 millisecond (0.01 s) which decayed suddenly to a value of 1.7×107 μgm−3 in the first 1 deci-second (0.1 s). The impact concentration at the point source by the end of the first second (1.0 s) was 3.2×105 μgm−3 which implied a 99.5% sudden decay when compared with 0.01 s concentration value at the emission point source. It is observed that air pollutants released from explosives/blasts get transported into the atmosphere in the first few seconds by forceful injection instead of by gradual dispersion as is the case with normal air pollutants plume releases. A mathematical control process was propounded (which is still subject to further research) to reduce the quick flow of air pollutants

Highlights

Air pollution is undoubtedly one of the signatures of volcanic eruption (Bluth et al, 1992; Read et al, 1993)
The intensity of explosion was initially linearly proportional to both the pressure and volume of air pollutant until different influencing factors like atmospheric stability, mixing height and atmospheric ventilation index set into changing its behavior to a negative parabolic shift with respect to time
This study revealed that like volcanic eruptions, air pollution from sudden blast is more of forceful injection into the atmosphere than gradual dispersion in the first few seconds of the explosion

Summary

Introduction

Air pollution is undoubtedly one of the signatures of volcanic eruption (Bluth et al, 1992; Read et al, 1993). In a broader form, gaseous air pollutants include all the gases that are found in the atmosphere above their normal ambient levels, while particulates include both solid and liquid particles that become airborne (Seinfeld, 1986; Hopke, 2009; DiGiovanni and Fellin, 2006; Smodis, 2007; Smith et al, 2001). Before there is an eruption, there is an explosion which is usually characterized by sudden release of energy that produces a sudden volume expansion (dV) of the conveying material due to large changes in pressure dP within the shortest possible time (dt). This causes pressure waves in the local medium in which they occur. These pressure waves can either be subsonic or supersonic (Bazarov et al, 1991; Slotnick, 2008); likewise, the explosion can be natural or anthropogenic

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Discussion

Conclusion